Testing apparatus for fluid tight casings



Sept. 29, 1936.

Vizi z/! f @I @Im H. WILSDORF TESTING APPARATUS FOR FLUID TIGHT GAsINGs Filed Nov. 1', 1935 @fig/? Patented Sept. 29, 1936 UNITED STATES TESTING APPARATUS FOR FLUID TIGHT CASINGS Hans Wilsdorf, Geneva, Switzerland Application November 1,1935, serial No. 47,898 In Switzerland November 10, 1934 s claims. (o1. vs -51) This invention relates to testing apparatus for fluid-tight casings and more particularly to apparatus for testing the tightness of watch cases. It is an object of the invention to provide an apparatus of this type which enables quick and efficient examination of Huid-tight casings by direct observation of the casing during the act of testlng.

The invention consists in an apparatus comprising a transparent receptacle containing a liquid into which the casing to be tested will be suspended, the receptacle being arranged to be hermetically closed, while means are provided to create a vacuum in the receptacle above the liquid level, so that when the tested casing would not be luidtight, air bubbles would escape therefrom to the surface of the liquid and such bubbles can be observed as the casing to be tested is suspended in a transparent receptacle of glass or similar material.

The accompanying drawing illustrates a practical embodiment of the invention.

Figure 1 is a vertical, axial section through the apparatus.

Figure 2 is a section along the line 2-2 of Fig. 1.

The represented apparatus comprises a receptacle l which is formed by a metal base 2 mounted on a frame 3, by a bottom including a flexible diaphragm 4 secured between the base 2 and the frame 3, by a glass cylinder 5 placed on the base 2, by a ring 'I placed on top of the glass cylinder 5, gaskets 6 and 8 being inserted between the cylinder and the members 2 and l, respectively,

and by a cover 1a being freely placed on the ring 'I which is secured to the base 2 by means oI screws lb.

The diaphragm 4 passes between two metal disks 9 and I0; the disk 9 carries an annular rim 40 I I guided in the base 2, while a connecting rod I2 guided in a recess I3 of the frame 3 is secured to the two disks 9 and I0 by means of a screw 12a. The rod I2 is provided with slots I4 through which passes freely a shaft I5 rotatably mounted in the frame 3 and carrying an operating handle I6. To the shaft I 5 is keyed an eccentric disk Il which coacts with two rollers I8 mounted on the rod I2 above and below, respectively, the shaft I5.

The cover 'Ica carries a stuffing-box I9 which is traversed by a tube 2!) provided, at its lower end with a hook 2| on which the casing to be tested is suspended. The upper end of the tube 26 carries an operating handle 22 and the lower half of the tube is pierced to form a passage 23 leading from a hole 24 in the tube to its bottom end.

When the apparatus is employed, the case 30 to be tested is suspended on the hook 2l, the cover la being removed for this purpose. The

receptacle I is lled with water, and the cover 'la with the tube 20 and the case 38 is put in place on `5 the ring l. The water also fills the space 3I -between the base 2 and the diaphragm 4, owing to holes 3,2v provided in the rim II. The diaphragm then occupies its upper position shown in full lines in Fig. 1. The shaft I5 is now rotated by 10 means of the handle I6, and the eccentric I'I, acting on the lower roller I8, pushes the rod I2 and the diaphragm Il downwards until this latter occupies the position shown in dot and dash lines. The water also descends in the receptacle 15 as the capacity of this latter has been increased, and above the water level there is created a vacuum. When the case 38 is not completely iiuidtight, the air contained in the case will escape in small bubbles which will mount to the surface of 2G the water. Owing to the glass cylinder 5 such bubbles can be observed and the place of leakage detected.

Once the shaft I 5 has been turned to bring the diaphragm 4 to its lower position, care must be 25 taken not to turn the shaft backwards by inadvertence, since bringing the diaphragm back to its rst position could cause an overpressure of the water in the receptacle and if the casing would not be tight, water could penetrate into 30 its interior and deteriorate its contents. To prevent such backwards rotation, a safety device has been provided which comprises a lever 26 rotatably mounted on a pin 33 carried by the frame and subjected to the action of a spring 28 35 tending to turn the lever in the direction of the arrow f. The lever carries a bolt member 2l and the shaft I5 carries an eccentric 29 against which the spring 28 applies the bolt 21. The safety device thus permits rotation of the shaft I5 40 through half a turn in one direction, but back- Wards rotation of the eccentric and the shaft is prevented by the bolt 2l. In order to bring the diaphragm 4 back to its upper position once it has been lowered, the lever 26 must be retracted 45 by hand against the action of the spring 28 in order to remove the bolt 2l from engagement with the eccentric 29.

When a testing operation is finished, the tube 20 is pulled upwardly so that the hole or holes 50 2li in the tube communicate with holes 25 in the stuffing box I9, and air can enter through the passage 23 into the interior of the receptacle; the cover 1a and the casing 3U can then be removed.

I claim:-

1. Apparatus for testing uid-tight casings, comprising a fluid-tight partly transparent receptacle adapted to be lled with liquid, means for suspending the casing to be tested in the liquid within the receptacle, said receptacle having a bottom formed by a flexible diaphragm, a frame carrying said receptacle, a shaft mounted in the frame, an eccentric disk carried by the shaft, means operatively connecting said disk to the diaphragm whereby a movement of rotation of the shaft in one direction causes a downward movement of the diaphragm and an increase in volume of the receptacle to create a vacuum above the liquid level, and means coacting with said shaft when the diaphragm has been downwardly moved, for locking the shaft against rotation and preventing return movement of the diaphragm.

2. Apparatus for testing fluid-tight casings, comprising a fluid-tight partly transparent receptacle adapted to be filled with liquid, means for suspending the casing to be tested in the liquid within the receptacle, said receptacle having a bottom formed by a flexible diaphragm, a frame carrying said receptacle, a shaft mount-ed in the frame, an eccentric disk carried by the shaft, and means operatively connecting said disk to the diaphragm whereby a movement of rotation of the shaft in one direction causes a downward movement of the diaphragm and an increase in volume of the receptacle to create a vacuum above the liquid level, a locking lever rotatably mounted on said frame, a second eccentric disk on said shaft, and spring means urging said locking lever into engagement with said second eccentric disk to prevent return movement of the shaft after creation of the vacuum in the receptacle.

3. Apparatus for testing uid-tight casings, comprising a iiuid-tight receptacle adapted to contain a liquid, means for temporarily increasing the volume of the receptacle to create a vacuum therein above the liquid level, a shiftable tube penetrating through the wall of the receptacle, means on said tube for suspending the casing to be tested into the liquid within the receptacle, said tube having its outer end closed and its inner end opening into the receptacle and being provided with a hole intermediate its length whereby when said tube is shifted outwardly relative to the receptacle communication is established between the interior of the receptacle and the atmosphere and when shifted inwardly such communication is prevented.

HANS WILSDORF. 

